I'm probably leaning too heavily on the original DS9 with this, but here's what I've whipped up.

Essentially capping off the pylons with another ring at the top and the bottom, and replaced the middle with the aforementioned "sphere" and the habitat ring with a federation mushroom.

I see the red bulb below more as an impulse engine than a fusion reactor - in case she needs to move in Emergencies or some such (hey - there's a precedent for it at least ).

That actually looks way more practical than the designs based strictly on the description from the book. The only problem I have with it is the fact that the impulse engine looks pretty wimpy. It's practically begging a bad guy to shoot it off